Experimental Gerontology ELSEVIER
Does bristlecone pine senesce?
R.M. ~anner".*,K.F. connorh
Abstract We evaluated hypotheses ol' scnesccticc in old trees by compariiig pi~t;~tivehiomorkers ol'nging in Great Basin bristlecone pine (Pirirr.~lot7,qtrrl.rr) ranging in age from 23 to 4713 years. To test a hypothesis that water and nutric~itcoiicluctio~i is impaired in old trees we exainined canibial prodticts in tlie xylein and phloem. We found no statistically significant age-related changes in tracheid diameter, or in several other parameters of xylem and phloem related to cambial function. Tlie hypothesis of continuously declining an~i~~alshoot growth incrernents was tested by comparing trees of varying ages in regard to stein unit productioti and elongation. No statistically significant age-related differences were found. The hypothesis that aging results from ail accumulatio~~of deleterious mutations was addressed by comparing pollen viability. secd weight, secd germinability. seedling hiortiass accumulation. and fi.cqucncy of putative mutations, in trees (11' varying ages. None ol'these para~netei-shad a statistically significant relationship to tree age. Thus, we found no evidence of mutational aging. It appears that tlie great longevity attailled hy some Great Basin bristlecone pines is ~~nacconipaniedby deterioration ofineristem I'unction in embryos, seedlings. or mature trees, ;In iiituitivcly necessary manifestation of senescence. We conclude that the concept of se~iescencc does not apply to these trees. ((1 2001 Elsevier Science Inc. All rights ~.eserved.
K~VII,IJI.~~.S:Bristlecone pine; Sene\cencc: Longevity; I'lhy.;iological agiiig: Aging: Pirllc.s lor1,yrrc~l~r
1. Introduction
A\ Peter Medawar put 11, :I pliy\~ologi\t wt\hitig to \tudy the problem 01 agtng f'rom \cratch "wo~tldlir\t of all try to plece together a hill eriipirlcal de\cnption of tlie phenom- enon.. ;IS it I\ rellected 111 strucrur-al change\ of tl\\ue\ and cell\ anti the type and Intensity of tl\\Lle and cellular mct,ibol~\m. Only \crnp\ of \uch tnfoiniat~onare now available he would have to collect tnore" (Medawar, 1957 40) A great ma\\ ol d,~taha\ \Ince accumulnted on what liappens to an~rnal\a\ they age - e\pectally ro Horrlo \tr/?rpr~r.Bitt surpr~\~ngly.llttle beyond conjecture ha\ been wrltten on the effect\ of agtng on the longe\r-11ved of orga111\111s- tree\ TIM\I\ probably due to the
0531-5505lOllli - \ec korit illotter 1' 2001 lil\cvies Scicncc Inc. All right\ i-e\cr\ctl PII: SO53 1 -55h5(00)00231-5 p~ncttc~tln'tt~i~e 01 1~3041t~ee rc\carch. wlt~cli,urn\ at procluc~ngmole 'inct better t~mberA not'tble exception 1s the jtudy by R,t,i\ ct '11 (1986) of trache~dlength in Gre'tt R,i\in b~~stleconcpine (P117irclorlqrrc~~o D K Ra~ley)They lo~111c1steady incte,i\e\ In thr\ par,t- meter lo1 .I\ much .I\ 2200 yea\. .inti clubbed tlie specie\ ,I 'record-bleaker' 111 wood .tn,itorny An ,tgc-~cl,~tcds~~blect th'lt li'ts ~ecci~eclmole 'tttcntlon in tree ~ese~irchha\ heen that 01 ph,i\e ch'tnge (Rl~nk.1902). the passage from ,I ju\en~lest'tge to m,ttu~~ty Phase ch'tnge 14 ,i1\0 tcrmecl 'ontogeriet~c,tl .ig~ng' Lyi el '11 (1967) cli\trngu~sheclluve- n~l~ty,rnatuiiiy. ,t~icl\cnil~ty ph,i\es, tllc 1,tttei w,t\ char,icte~~/edby g~owth\lowclou~i 'ind sc,int~nc\\ol Iru~t~ng.'tnd very old [lee\ were \,tlcl to prolong the11 I~\csby cxtend~ngthe ph'tse 01 \cn~lrty Ph'lse cIi,i~ige In tlees 14 of concern In forestry hecause ~t aflect\ such plie~iorne~t~t,I\ 'ige of flowel lng .inel \LICCC\\ 01 \ cget,itrve prop'tgatlon ((;reenwooct, 1981) Also of I~nportanccIn lore\try I\ tlic concept ol 'phys~olog~c,tlag~ng'. wh~ch 1s seen as the c,at\c of s~iclirnorpliolog~cnl changes as tlic 'tl,~ttcn~ng'of con~le~crown\. ~nc~-e,ised \u\cept~h~l~tyto d~\e:tses, c~~id1-ed~lcec1 ct~i~i~ir~l 11nggrowth It I\ apparently \ynonymous wrth \enewenee. but clear def~n~t~on\of the tell11 '11 e eltls~ve Fore\te~\vlew the poor de\elopnwnt ol young t~ee\on dep~u~pc~~tte\llC\ '1s 'I rn~tn~lest~tt~otiol physrolog~cal aglng. regatdles\ ol the cliionolog~cal'ige ol tlie t~eeDendroclironolog~sts u)~nriio~ily invoke phy\~ologicalaging '1s ,I factor In tlte I-educt~on01 growth ring\ In olcl (lees that mLi\t he corrected lol- when Intcl-1)1-etrngtree-11ng clironolog~es(Fr~tt\, 1976). Unfortunately, most of [lie cmp~r~calcompai-rson\ of young v5. old trees that one c't~i find In the 11tcratul-e,Ire ba\ed on trees that d~dnot contrast greatly 111 age, because there was Inore concern wtth the tree'\ commerc~alde\elopment than 11s b~olog~calI~fespan For example, Forward and Nolati (1 964) looked for aglng elsect\ on red p~nes(P~IIL(\ ~C~\IIIO\(I Alt ) c~hoseInaxlrnum age ulis 50 yeals, o~ily,tbout a s~xthof the spec~es'lifespati (Altm~in'tnd D~ttmer.1962). A h~ghly~nfl~ient~al paper by Mollcr- et al. (1954) dealt w~ththe photo\yntIies~\/resp~r;~tonratlo ol European heeche4 (E'lr,ylr\ ,\ll~trfritrL) aged ,I maximum ot 85 years compared to '1 lrle\pan tliat occa\~onallyexceed4 900 years (Busgen '1nc1 M~lnch,1929). Greenwood ( 1984) compared \hoot developnient In loblolly plne (PIIIII\f(r('il(l I,) sclo~is(ilkell 110in OI tet\ Ktliglng I~omone to 12 years of 'tgeAnd In 'inother ~nfluentlalpapei In whtch conclus~onswere dl-awn on the 'iglng ol Scot\ plne (I'117irs \\l\.r\trr\ I>), W,ire~ng( 1958) rclx)~-tedon a \111gle5-year-old branch taken f~oma (lee .1get1 13 yearst In several studlcs 01 'tgc-related changes rn the cainb~algrowth ol \~CIIIOU\ plnfi, the outel 11ni1t\of .kge were 30. 130, 140, ,lnd 600 ye'irs (Scholtes, 1953; Er~tts.1969, 1976: Mikol't. 1950) In ~ecentye'us, t~eepliys~oIogist\ h,~\e sliown ~enewecl ,~w,uc~ie\\ol ,tge-~el,ttcdchanges 111 11-ces, a\ they tty to better tlnder\tand 'old-growth' forests ,utd tlic lo\\ 01 ~I-~CILIC~IVI~~w~th~ige (K;it~l~ii;tn~i rt~id WIttl\l~i\. 1990: Yodel et a1 , 1994: Kauf mann, 1996; 1Hubb,11d et '11 , 1999) Most of these efforts have focu\ed on pliotosyntlies~\'tnd w'itel tKtnsl)olt ?'he t~rstsc~cnt~f~c conle~ence clevoted to the ~sstles of dc\elopriient ,tnd 'tglng rn lo~c\t[lee\ tooh pl'ice In Italy 111 Septe~iibe~2000. contcm- pot;~neo~l\ly~~th the conletence '11 wh~chtl114 p,tpel w,~sprcsentecl
2. Our studies and okjectives
Thougli tlieie h,is neccl becn ,I 'full emp111c.11de\c~~ptlon' ol the ellects ol .iglng In tree\. Inany ~nve\t~gatol\have a\\umed wch effect\ cx~\t,and have trled to rat~onall/e the111 Some ot their explanations are vague. but 'I few 'ire testable U\~ngthe world'\ olde\t known tree \pecle\, Great Basin br~\tleco~ieplne (P lor7g(w\~rr),a\ our te5t organ- ism. we have \~~blectedthew te\t,tble proposal\ to observat~onor experiment, In a \earth lot blorn'~rke~5 of 'iglng (BoddC. 198 I ) Thl\ reflects our '15\umpt1on that 4000 yem or \o \hould p~ovlde,tniple oppo~tuntty lot aging blomc~tl As a [tee get\ older, larger. and mole complex. water tlan\pol-t problerns cleate ~ncrea\cdw'lter \tre\s. Th~sre\ult\ In tIlni~nr\hedgl-owth 'tnd hormone production, and ft11,11ly,death (Went, 1942, Jank~eu!~c/'tnd Steckl. 1976. We\tlng, 1964 See cll\o Hubbarcl et al , 1999, Ry'tn ,lnd Yodel-, 1997) Water tran5por-t rn {lee\ takes place In the i'lpwood, the more ~ecentlyIalcl clown 'tnnu'tl 1ncrement5 of wood fo~lnedby the latela1 melistem (camb~u~n)that clothe5 the trunk, branches, and root\ beneath the bark The cells I-e\pon\~blefor till\ tran\por-t In contfer\ arc the trache~d\,\prndle-\haped cells that are or~entedlongit~idinally They dle and develop empty lutnen\ \hoi-tly 'liter torrn~ng,and they are ~nterconncctedby opening\ known a\ p~ts.W'tter taken up in the root\ pas\e\ through the va\cular \ystern ent~relywlt111n trac- heids untll it enter\ the leave4 Centrilugal to the wood, or x)llen~,15 the phloein layer wh~ch14 formed on the outs~deof the cambium wh~letracheids forrn on tt\ in5ide. Phloem cell\ transport mainly carbohydrate \oluttons made tn the follage, the product of photo- synthe\l\ Unllke trache~d\,which must be dead to funct~ona5 ptpe\, phloem cell5 must be allve They are \hart-ltved and fonn only '1 very narrow \heath between the camb~u~nand dead bark t~\\ue\ So to add welght to our trache~d\tud~e\, we ,i1\o observed \erne par,imeter\ of pl~loem. We chow to \tudy the dlarnetci-5 of the tracheld4, to \ee ti they become constrlctcd over the life of a very old tree If so, w'itel lnovement could be impeded We al\o \ampled llvrng tree\ to detect, by color change\, how th~ckthe \apwood I\ 111 tree\ of drllertng age, and how many year\ of l~vtngray cells there ale In tree\ of d~fferlngdge Kay cell5 form rac51,tI ribbons w1t111n the wood '~nd phloem. They 'Ire '~l~vc111 the \,ipwood. dead In the heart- wooci We ,dso compared phloem thickne\\ In tlee\ of d~ffer~ngage. Age- elated changes rn ,my ol thew pclralnetel\ could ~ndlc~ttea canib~um rn,~llunct~o~~~~ig due to 'iglng, perhaps '14 CI le\ult ol 'repllcatrve \ene\cence5 (Campls~.2001) A\ ,I tree ,ige\, the ploportlon ol photo\ynthct~cto non-photo\ynthet~ctl\\uc caum 'ln unlavorahlc pIioto\ynthe\~\/re\p~rat~or~balance. le\ulting rn grntl~laldecllnc anti \uh\e- cluci" death Th14 hi14 been \ugge\tecl 111 \evela1 ver\ton\ by Jacob\ (1955). Moller et '11 ( 1954). Mo114ch ( 1929), WooIho~i\e( 1972), Wright and Mooney ( 1965) and Gerrl\h ( 1990) The concept ha\ heen made mo\t expl~cltby W'ilelng ( 1958, 1959) and Moorby ,~ndWarelng (1963). who operationally ciefined aging In woody plan{\ 34, among other tralt5, the 1054 oi VI~OSii\\~c~;~ted w~th decl~~llng ,tnnual ~ncrement\ol \hoot g~owth,and therelole decl~nlngphoto\ynthet~c tl\\ue. over the yea15 Nearly all tlie photo\yntl~e\~\111 o~lite\t 01-g,uii\~noccur\ 111 le,tve\ (needle\) that arc formed In wlntel- bud\, and growth of the tree'\ crown 15 dcte~mrnedby the growth oi \hoot\ formed by elongat~onof the bud\. We theretote \earthed fo~age-related cli,~nge\111 the nurnber of needle5 lorrned in the h~~cii,tnd 111 [lie amount ol new \hoot giowtli emunat- Ing Irorn thew bud\ A\ ,I tree ,Ige\, e\peci'illy ,it ti~gllclevatlon\, co\nilc rdy bomb,i~cl~iienteventu,~lly cau\e\ the ,lccurnul,lt~on of deleter~ou\rnutatlon\ that 1c4ult In ~n~~llunctton~le'iding to death (S'ix, 1902, We\t~ng.1964) I11 Piril,\ rt I\ rel,~t~vely ea\y to ween lai ge \ample\ lo1 ev~tlenccof put'ltlve rnut,ition\, using pollen, wed\, and $eedl~ng\Mut,ltlon,il lo'~dciecr-e,l\es pollcn ~i~tb~l~ty(B11gg4 itncl Kliowle\, 1967), 'ind inv~ab~l~tyc'in be detected In labor,itory Seed I~omtree\ ol vartou5 ,tge\ can be \~tbjectedto gelmlnatlon te\t5. the re\ult$ ot which coulcl be c~llected by mutational load Seedl~ngg~owth I'itei c,in be ,~fiectedby mutation, 'lnd CIIC eauly compru-ed lor b~o~na\\ciccum~~lc~t~on Fin'llly, uvng \eedltng\ grown 11om the \eecl of vanou\-,~ged tree\, one c'in 5c1ee1-1for '\tand,ird' prne \eedllng niut,ltlon\ (F~anklrn, 1970, 1977) 3. Materials and methods We \ampled Great Bas111br15tlecone pine\ Irom n,~tur,~l\t,~nd\ In the Wli~tcMountaln5 ol \o~~thea\ternCal~lorn~a (Inyo Nat~on'tl Fore51 Meth~~\elahGrove. I"tt~~,nchGlove. Carnplto Mount,itn) 'lnd from M,~mmorh Creeh ancl the T'tblc Cl~fi\111 \o~lthe~nUt,lIi (DIXI~N,~t~onal Fore\[) Elevatton\ tanged iron1 2835-3505 In 111 the Wli~teMo~lnta~n\ to 2560-2896 in ,lt the Ut,tIi \Ite\ To Inln11ii1/e env~~onment,tltnipact< we ,il\o ~t\eddated br~\tleconcplne core\ t'lken In plevlou\ ye,tt\ I~ointlec\ In the White Mount,l~n\.und arch~ved,it the Labor,lto~y ol Tree-R~ngRe\cai-ch at the Unive151tyol A~~/on,tT~ee 'Ige\ v,lr~cciIn the \eve121 studle5, w~thextlcme\ 01 225 ,ind 471 3 ye,u\ For \tud~e\oi xyleni ,uid pliloe~nwe it\ed ,I \te~eom~croscopcecl~~~pped w~th ,I ci~,~w~ngtube '111d 'I co111po~nid mlclo\cope equ~ppedw~th ,I 35-111m c,linei,l. IKI ,Inti tolu~clinebluc ,i\ \t,nn\, glycol ~iiethac~ylate.I\ ,in embedd~ng med~um. ,nid Cla\\~fic,lt~on,111d Reg~e\\~o~iTree (CART) ,lnalyw\, ~~~~iciom~/at~o~ite\ts, 'inel IIII~~II ~eg~c\\~on, to ,ln,~ly/e cl,~ta (Conno1 ,~ndLatinc~, 1990) OUI needle development ,111ci \hoot g~owth\tud~e\ tlt~l~/ed [lee\ 'lged 14-2052 ye,u\ Ironi M'nlii~ioth Cteeh ,~ndthe MetIiu\el,~h.lnd P,~t~~,i~cliGlove\. ,uid utrl~/etl CART ,lnaly\~\,~,~i-tdo~ii~/at~on te\t5, ,111d 11ne'tl 1eg1e5\ion (Conno1 ,111d lA,inner. 1989) The pollen, \eed, 2nd seedl~ngstud~e\ utrl~/ecI [lee\ 700-171 3 )/c,u\ old from tlie Mammoth ,tnd Meth~~sel,rliGrove srte\, tet~azol~urnchlonde ,I\ ,I v~t'll\t,tin lo1 pollen, g~eenhott\ecul1~11e to1 the secdl~ng\,,tnd CART and I~ne,t~legle\\lon .ln,~ly\e\ (Conno1 ,inti 1,'lnnel. 190 la) 4. Our findings The find~npbelow. ~ep~escntonly .I portlon ol ~LIItotal ~e\ult\.d~le to lirn~tat~onsof \1?.tw For ,i coniplete \t,itcment ol ~LII-~e\~~lt\. \ee Connor .tncl I,,tnnct (1989. Ic)90. 1991it.b) The concl~l\~o~i\c11,twn. however. ale co~i\r\tentw~tli ,111 01 ~LIIicsult\ At all Iocat~on\,there w,l\ no con\i\tent dge-related trend 111 me'tn tr.tche~d dl'tmeter At M,l~i-~~iiothCreek, three out of 1ou1-tree\ exh~b~tedIncre,i\es of trachelti d~ariietcl-(Fig 1 ). In tree TRL 80-209 (2047 yeat-\ old) the upw'trci trend w,t\ cvrdent for the pa\( 100 yeat\ At the Methu\clah Grove, three out of lour tree\ showed ,I recent ti,tche~cl dlumeter tlrt r-cwtr, the exception he~ngtree TRL 80-140 wh~chat 1162 yc'ir4 w,t\ the \econd olcle\t (Fig 2). At Camp~toMo~tntain all Sour- tree\, r~tnglngIn .tge 11-om 94Wo 128'3 year\, showed rccent tl-achcrd d~a~iieterInclea\es In tree TRI, 83-176 that tiend Iiacl la\tecl '300 years Arid at the Patl-larch Grove. three out 01 lour trees aged 875- 1253 year4 had clearly Iricreasrng trachcld ci~ameter\over the 1351 cer-~t~~ryAll 01 the4e recent trend4 lollowed CL 11let1meol pel-1od4of tl-achetd diameter ~ncl-ea\eand decre>i\ethat did not follow a v~\ually appai-ent general trend Thus he founcl no ev~denceof 'carnb~al'tgrng' among even the olde\t of the\e tree\. Nor were there any cons~\ter-Itage-related change4 111 other ch,tracter\ that are related to 1;ig. I. Mcalr ttxcheitl tl~;inie~er\Ssoni I'our (;rc:it II:i\ilr hsi\rlcco~repine tree\ I'I-o~nbl;i~~i~~rorIi ('reel,. (:'I' (nrotlifictl ii.otn ('onnol- ant1 12annes. 1900). Fig. 2. Mean tKichcid tliamctcr\ l'ronl Sous Great Bn\in hristleconc pine tree\ from tlic Methurclnh Grove, CA (~rroditieclfrom Connor I .;~nner.1900). cambtal performance - \apwood th~ckncss,nuinber of growth layers In the sapwood, mean radial (ring) growth. ray cell longcv~ty,number of growth layers In the phloem. pliloen~tltickness, and annual phloem (s~evecell) production (Connor and Lanner. 1990). At all the s~teswhere trees were sampled fix bud and shoot stud~es,there was no sign~ticantrelat~onship between age and the tree shoot parameters studled recent annual shoot length, production of stem unit\ with~nbuds, and final 5tem unit length In other word\, there was no detectable age-related trend In the ~norphogenes~\ol \tern units w~th~n bud\ (Lanner, l976), or the elongat~onpotential of those stem units In determ~n~ngfinal \hoot length (Fig. 3) At Mammoth the 1984 \hoot length\ 01 the 5 younge\t trees dveraged 35 mm. the 5 mect~an-dgedtrees. 22 mm, ,ind the 5 oldest trees, 38 mm At the Methu\elah Grove, the coriesponding niean\ were 15, 12. 'ind 16 Other data show sim~larly~ncon\i\tent trend\ (Connor dnd Lanne~,1989) The result\ ol this \tudy do not \upport the content~on (W,iieing, 1958, 1959) that aglng 1s ~nd~ca~edby ,I d~mini\hmentol annual \hoot length, 'ind theretore ol leal production as well. Pollen vrability was generally poor fixall 41 of the trees \ampled [I-om Mammoth and the Methu5elah Grove The legession of percent pollen viab~l~tyon tree age wa4 not sigi1111c~1ntat e~ther\~tc o~ when data were cornbilled (Cotinor 'liid Laiiner, 19912) Meail pollen vi'1bt11t)l from the 5 youngest tree\ 111 the stucly (mean age 137 yea14) w,t\ 18 ?(h. lroi11 tlie 5 ined~an-agedt~ee\ (meail age 985 years), 6 8'h ,ind fro111 the 5 olde\t (inean age 2,172 yea)\). 5 9(/c The CART analy41s. however, dlti not pl-oduce a b~narytree with ~he\ed'it;~ Seed we~ghtalso showcd no \tat~\t~cally\~gn~ficant or con\15tent age-related t~etid, e~therat Mammoth or the Methuselah Glove (FI~4A) The mean we~ghtsol slxteen ten-wed lots (each lot from a sep'irate \eeci t~ce)front M'iinrnoth were. Irom the 5 younge\t A Annual Shod Length 6 Number of Stem Untts 7 Y M 0 Age (Yew Fig. 3. A, 13. Shoot gt-out11chat-:~cteristics of aging Great Basin hrisrleconc pine. Fi\e youngest trccs (Y)arc 883- 1219 year\ old; five mediitn-;%zedtrccs (M) at-e 1564- I943 qcirrs old, and live oldest trccs (0)arc 2863-32.56 years oltl. Bars indicate tilean\ and [ranges. Data fro111Methusclah Grove (Connor and I>atlner, I'IXC)), gr:ipli fi.om [Finch. 1099. tree\ (mean age 344 year\), 0 123 g; the 5 med~an-aged(mean age 876 year\), 0 107 g; and the 5 olde\t (mean age 1239 years). 0 104 g. At the Methu\elah Grove. the corre\pond~ng \tatl\t~c\for \eventeen ten-\eecl lot\ were 0.069. 0 091, and 0.064 g, w~thmean age\ of 1006, 1732, and 3062 years, re\pectivcly Seed gcrm~nabil~tywas al\o unrelated to tree age (Fig 4B) The \eed lot\ w~ththe highe\t ger~n~nab~lity,78 and XS%, re\pect~vely,were troni the two oldat tree\ in the \tudy, TRL 80-1 38 (4257 year\) anci the Methu\elah tree (4713 year\). -Thew rewit\ are \upported by tho\e of Johnson and Johnwn (1 97X), who ger~ii~nated,111 36 weds taken II-om a cone of the Methu\elah tiee Our re\ult< ,~l\oagree w~tha little-not~cedfig~l~e c'iptlon In Edmund ScIiulman'\ Ianiou\ report, Br-rrflvcorlr Pirlr, OIdprt K1701t 17 L~i>rr~y 7'l11rl,y,which dppeared in The Nat~onalGeographic Magal~ne(Sch~lrn~~n, 1958 365) It read4 "Seed fl-orn an Old Pine Grow\ 'i\ V~goiou\lya\ Thdt from ,I Young\tei Dr Fr~tsW Went hold\ baby pine\ he grew from the cone\ ol '1 100-year-old and ,I 1500 year-old tlee By v'lrylng growth cond~tion\art~lic~ally, Dr Went hope\ to learn whethe1 old bri\tlecone\ differ b't\~c'llly from young one5 " The photogr,lph accomp~tnytngth14 captlon \how\ the ein~ncntbotan15t FII~\Went peerlng dt a container ol \IIIIII~~\eedling\ frnm each ol the two t1ee4 El14 conte~nplated l~t~thei\tudle\ \eem to have not 111'1terl'lll/ed Seedling b~om,t\\WCI\ detet mined by obt,i~n~ngoven-dl y we~ght\ol g~eenhou\e-giown \eedling\ 'liter 30, 60, 90, ,~nd120 clily\ The \eedling\ were plogenre4 ot the tree\ lrotil M;1iii1iiotli 'tnd the Methu\el,lh GIeve LI\C~111 the work cte\ct ibcd above 01 the M,~~nniotli- o11g1n\ead\,5 1 (h01 29 1 I \eed\ germinated Of the Metliu\elah Glove-or1g111\eed. 6 l r/c of 7986 gwniinatccl There were no \tC1t~\ttcallysign~ficant ~el,~t~on\li~p\ hetween ,I [lee's .lge 'lnd the bioma\\ ol ~t\off\pr~ng (FI~ 4C) F~nally,only two pLlt,ltlve rnut,ltion\ wele louncl among the \ceclliiig\ grown from K.M. Liri~i~ci..K.1.'. ('oi~iloi-/ I~.'\l~c~i.ii~ier~~~il(;ei~o~~rolojii. .ih (10011 67.7 -68.7 Fig. 4. /\-I>. Seecl ;tntl \cctJling charactcsi\ric\ of ;lgit~gC;rc;tt 13;i\in hri\tlcco~lcpint. Age gr-oup\ (11 - 5) nse young (Y)700 1260 year\ old (III~;I~= 1006). nlcdian (M) 1558l045 yeat-\ olil (mcan - 1732 yc~~rs).;ilicl old (0)1'195-4713 yc;ts\ (mcan -- 3062 ).car\). 13;1s\ intiicale mean and rangc ill A :itid B. C \how\ \ccdlil~ggro~\lIi of iuo inch\ itlu;rl\ Ssotn tach agc group I'rom the Mctli~i\clal~alld M;immorh GI-eve\. D \ho\vr fscclucncy olputali\e niutanl \ecdlilig\ gt-o\\n Sro~n\cctl l'rot~rIree\ of hot11 grove\. 1h1a fro111Control- cilid I~clnnes.I90 la: gsapli\ fsotir l~'it~cli,lc)Ocl. M,tmmoth tree5 Thew were plant\ that had yellow oi pale green cotyledon\ (\ccd leave\) ,~nd;I recl \tern, ~n\teucloi green. Bot11 were froin an 83-3-year-old tree. Neitliei \~ii-v~vcdtor (10 dcty\ Twenty-tlve \ecdllngs of Methuselali Globe o~lglnh,ld .their,i~~tplgmentcitlon oi m,~ltormedcotyledon\ The inother tice\ vctiiecl in ,igc Iiom 1539 to 37 13 yc,ir\. ,ind all the\c \eedling\ died prio~to the 60-d'ty heir vest Altlio~~ghthe numbel oi p~lt,ttibemutant\ irom the thice 'lgc-clas\e\ of tlees fiorn the Methti\elah Glove \~igge\tan ,lge t~eiid(F1g 3D), 11 \rgnillc~u~ticlatioii\hip W,I\ \~~pportedby ncitl~ctiegre\\ion nor CART ,in,ilyse\ Thciefore. we wele unable to t~ndcviclence that r)~lt~it~veI~ILI~~I~IOII I.;I~\ were rel,~tedto ti-ee .tge "1 the4c 131 ~stleconcpine4 ol gie'1tly contr ,~\tiiig ,tge\ iioin M'inimoth 'incl the MetIiu\el,ih Giovc 71ec\ glow by the act~v~tyol metl\tem\ - trss~~esth'tt 1et~t111tcttlpotent cell\ tor 'inother g~owthcycle, wli~lemo\t ot the cells crc,tted 111 the pre\ent g~owthcycle drfle~ent~,ttcto lo~msl~wc'l~/ccl tl\\ue\ In ,In ~dc,tltree c\cry b~tof stlrf.tce ,irc,t of root. t~unh.111nh. .tnd br,inchlet woulcl be ~rnclcr1,trn by ,I contln~ro~r\\he,tth ol merrsterll - the caicular c,~lnh~ir~n 'ind e\ el y \hoot c~~i~l~oottrj) wo~~lclbe tcr mrn,ttecl by ,in ,tp~c,tl rilel I\tem III~LIII~\\n\t,ttnecl o~e~a I~fct~liie. howe\ler, ~xtrt~~illyco111lxonli\e the Integl~tyot thrs \) stem ol rnelrstcrn\ The drtte~cntr~tlg~owth pel lor rii,tnce of ,I t~ccover tllnc I\ t1iereio1-c ,I cl~~ectcon- \ecluence of the cl~ltercritralpcrfo~nl~tnce ol 115 mcrl\tcrn\, and ariy lac to^ that ~nod~frc\ a t~ce'\g~owth mu\t do \o hy mocl~fy~ngmcr~\tem,ttrc beh'tvlol In the \tucl~es\umm,t~~zecl here, we found no ev~dc~iceof ,111 ,igc-~el,ttccI ch,tnge 111 the clu,tntrt,tttve or quCtl~tcttrvehchavror ol c,tmb~al o~ ,tp~c,il metl\tcm\ No1 tlrd we lincl per\Ll,t\r\e ev~denceol enh,incecI t;ttc\ ol 5pont'tneoLrs m~rt~tt~onIn the pollen 01 seed of very old tree\ We r~i~rsttheleiore conclucle thd the age-related changes 111 tree\ that li,t\e been r efer I ccl to ,I\ ~~liy\~olog~c,tl,nierlstematlc. 01 rn~rt~tt~on~tl'tg111g 'tncl s~~b\urncdIn the term sene\ccnce, do not ,tppe,u to 'tpply to Gre'tt R'is~n131-~stlecone prne What then rnrght 'recount lor the ohv~ou\mo~pholog~c~tl ch,tnges that rnake old (tee\ \o d~flerent In 'tppearance Iron1 young tree<, a\ide l~olnthe '\ltng\ and arrows' ot lrie rt\eit j SLII-ely.11 tht\ yue\tlon I\ dddre\\cd by otlier ~nve\t~gator\, rliany po\\~hleali\wer\ may he \uggestcd We wi\h to ni'tl\e just one sugge\tlon, however. wli,tt 'tppe'tr- to be Ltge-c't~~\eclch,ingcs 111 [tee hdbrt coulcl he due to nutr~entdelicrt\ c,lused hy tlie 'm~nrngout' 01 the \o~llrorli wh~chtlic tree dc~ive\ 11s mrneral re\ource\ Especr;tlly 111 rocky teir,trn rnh,thtted by the toot\ ol other tree\, ,I tlme wrll come wlierl the 4011 ~ivCtrl;tble1o1 'I ~ICC'\ prospect~ligwill 11,tve lo\t more riirt~~ent\t1idr1 I\ 17e11ig ~eplcnr\hcd 11o1n ~ecyclrngon the sutl,tce o~ mrnet,tl~/,tt~o~i01 the bedloch Ftom th~\IIolnt on, the t~ecw~ll he ol~cr~ttrrig111 ,in cnvllonment 01 ~cducedr~irt~~t~o~l. mcl rii'ly 'IP~C'II 10be ,I \ene\clrig or-g'tnl\m, e\en 11 11 I\ not. Wh'tt then ol death j I\ tlicie 110 1111111 to the 11lc ol ,I non-\enescrng plne ) Must ~t not clre soulccl,ty. 'tncl 11 \o. of wh,tt7 Sch~rlrn~tn(191'3) N,I\ the f31\t to j3o111t ant the co~tel~ttron between long lrle ,tnd II~OIOLI\ h'it~t'tt l,tl\e h~m,we hclieve thd the 11gor\ 01 ciry, li~gli- clcv,it~on\Ites educe the Itl\elrIioocl ,trici ~nte~i\rtyol c~ttc~ckhy rri\ect, I~~tig~tl.'tnd verte- br'ttc 17mts Even mo~c~ntluentr,tl m'iy he the low l~ccluencyol 111eon \rtes w~thsc'tnt ccget,ttr\e cover One ol u\ h'ts \ugge\tecl th,tt 11 .I tree ,t\olds ~t\pest\ long enough, rt wrll e\entlr,tllq \i~ccunihto so11 ero\lon. ,ti its root\ ale cIcl711\eclol their ,tnchor,tge (1,anncr. 1083. 1990) TI1114 11 UOLIICI he preln,ituic to ~~o\ttrl,tte~rnrnort,tl~ty c\cn lor b~~\tlcco~le pr11es Acknowledgement\ Thr\ PCI~XI I\ ded~c~tt~lto 111 kicl~li~~~idSch~rlm~t~i. uho 111 \t cleter~ti~ncclthe cxr\te~iccol 4000 year-plu\ tree\ In hrs \tudle\ of Great Ravn brrstlecone pine rn the Wh~teMo~tntain\; 'tnd who expre\\ed the hope that "when re\earch ha\ been carr~edfar enough in thew Methu\elah prne\, perhap4 the~rmi\\hapen antl battered stern5 wrll glve 115 an\wer\ 01 great be,~uty(Schulman, 1958, p. 368)." References Altnlan. 1'.1 ... Ilittmer. I1.S.. 1962. (irouth. Including liept-oduction ;inti Morphological Ilcvclopmcnt. I:ctIcl-n~ion of' Antcrican Societic\ l'or Experimental Biology. Washington. 13;ins. P.. Schntid. I<.. \;in Heu\;cn. l3.J.. 1986. Wood anatomy of P. Ior~,qtrc,~,tribt-i\tlcconc pine) ant1 the ru\t:tined length-on-age increase of it\ trncheid\. IAWA Bull. New Ser. 7, 22 1 --228. BoddC. T.. 108 1. 13iomnrker\ of aging: key io a younger life'!. Bio\cicnce 3 1, 506-567. Brig\, F.N., Knoulc\. 13.F., l9(77. Introduction to Plant Breeding. lieinhold, New York. 131-ink.R.A.. 1'-162. Ph;t&c change in higher plant\ and \onlatic cell he[-eclity. Q. licv. 13iol. 37. 1-22, Bii\gen. M.. Miinch, E.. 1029. The Structure and 1.iI'e of Fol-e\t Trees. Ch;rpman Kc Hnll. IAondon. ('ampisi. 3.. 2001. !;!-om cell\ lo 01-gani\ms: can we learn ~thoutaging froin cell\ ill cultut-c?. lixp.